Engine starter



' Oct 6, 1925. .556.38

H.. E. VAN NESS v ENGINE STARTER .F'iled June 28; 1918 INVENTOR. J '6? 76% 71M 4% ATTORNEYS.

By JM 49M x Patented Oct. 6, 1925.

UNITED STATES HENRY E.

VAN NESS, or ELMIRA, nnw Yoax, ASSIGNOB 'ro Ecnrrsn MACHINE com- PANY, or ELMIRA, NEW YORK, A CORPORATION or NEW YORK.

ENGINE STARTER.

Application filed June 28, 1918. Serial No. 242,347.

To all whom it may concern:

Be it known that I, HENRY E. VAN Nnss, a citizen of the United States, residing at Ehnira, in the county of Chemung and State of New York, have invented certain new and useful Improvements in Engine Starters, of which the following is a specification.

My invention relates to a starter for engines, more particularly internal combustion engines, and pertains to the drive or transmission portion thereof between the starting motor and the part, such as the fly wheel, of the engine to be started.

The object of my invention is'to provide in such a drive or transmission a means for transmitting the power therethrough initiallywith a yielding pressure and finally with a rigid or positive pressure. Indrives 'of the class and character to which my inventionis particularly applicable a yieldin driving connection in the form of a coiled spring is provided to transmit the power yieldingly and also to store up 'en-. ergy until the .fly wheel is broken loose and started. Such a spring has its limits and in order to prevent any overtaxing of the spring and to provide a positive or rigid drive when the tension limit of the spring is reached and to thereby prevent setting of the spring, my present invention is employed.

Speaking in general terms andv referring to the particular embodiment employed, my invention consists in providing means whereby the power will be transmitted to the rotatable member or screw shaft yieldingly through the spring until the spring has received a predetermined amount of angular deflection whereupon a rigid or positive driving connection will be called into play at a predetermined point below the elastic limit of the spring, thereby relieving the spring from the further and greater degree of power transmission but without. interfering with the flexibility of said spring within safe limits.

' In the drawing Fig. 1 is an elevation partly in section of a drive embodying my invention. Figs. 2, 3 and 4 are cross sections I on lines indicated by corresponding figures and looking in the direction of the arrows,

and Fig. 5 a plan view of a portion of the drive shown in Fig. 1.

For convenience in illustration and 'dea driving shaft 1 on which the drive ortransmission is supported and by which it is driven. To the outer end of this shaft there is secured hymeans of the pin 2 a driving head in the form of a collar '3 (through which said stud passes and thence into the driving shaft) and a cylindrical inwardly projecting extension 4. The

screw shaft 5 is here in the form of a sleeve or hollow shaft fitting upon the driving shaft 1 and is operatively connected with the driving head 3 through the coiled driving spring 6, one end of which is anchored to the pin 2 and the other to a stud 7 which screws into the driven head portion of the screw shaft. As shown such portion is integral with the screw shaft, but this is not essential as it may be made separate and detachable and secured thereto.

Upon the screw shaft is mounted the driving member which is in the form of a pinion 8 screwthreaded on saidshaft and adapted to mesh with the teeth 9 of the fly wheel 9 of the engine, according to the particular installation illustrated.

The description so far given is applicable to said -Eclipse-Bendix drive and the differences thereover, ,now to be described, particularly concern my resent invention. The extension 4";is provi ed with one or more, preferably two, projections or tongues '10 which are adapted to be received b and to operate within-the-slots 11 forme by and between the-projections or tongues 12 extending outwardlyfrom the outer end of-the screw shaft or its driven head 5. As shown in Figs. 2 and 3 the slots 11 are of a length to permit of a partial rotation of the tongues 10 before the come intocontact with the tongues 12 an thereupon and thereafter constitute a rigid or positive driving connection and transmit the power instead of the spring.

Thus initially the power is transmitted from I the driving head 3 through the spring 6 and after a predetermined amount of angular deflection of such spring which is thereby cushioned, the tongues 10 and 12 are brought. into contact and the further power is trans-- mitted directly through these driving heads and notthrough the spring. lhe screw shaft is thereby rotated or driven initially with a yielding pressure through the coiled spring and finally b a positive pressure directly through said riving heads. in this manner and loy these means the driving spring is enabled to perform all of its intended fund tions and is relieved against any breakage or damage that would result in case of too great angular deflection which would cause a permanent set in the spring.

This construction also takes care of the rebound of the spring (which has a tendency to expand the spring and cause breakage) inasmuch as excessive expansion is prevented by the contact of the members 10 and '12, moving relatively in directions the opposite to that when acting to relieve the spring of excessive torsion strain. Thus this means limits the relative movements of the driving and driven elements in both directions.

Although it have described my invention in connection with a drive of the so-called single reduction type, in which the driving equally applicable to the double reduction type in which the starting motor is indirectly.

connected as by gearing with a. driving shaft, both of which types of drives are exemplified in Bendix Patent No. 1,125,935.

'lhe construction of the heads together with their tongues and slots is such that a yielding longitudinal movement of the screwshaft is permitted in the event that the pinion teeth should abut the flywheel teeth end to end. Y

l claim:

' A transmission or drive for engine starters including a driving and a driven element, and a spring operatively connecting them for-initial driving, said elements having complementary tongues and slots permitting a limited relative movement one with respect to the other and adapted to operatively engage each other for direct driving at theend of such limit, the said tongues and slots being so constructed and arranged as to permit the driven element to move longitudinally in either direction with respect to the driving element and said tongues being norn'lally positioned in contact with one side oi their slots.

HENRY van NESS. 

